mirror of https://github.com/vuejs/core.git
41 lines
1.4 KiB
TypeScript
41 lines
1.4 KiB
TypeScript
import { ref, isRef, Ref } from './apiState'
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import { currentInstance } from './component'
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export interface InjectionKey<T> extends Symbol {}
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export function provide<T>(key: InjectionKey<T> | string, value: T | Ref<T>) {
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if (!currentInstance) {
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// TODO warn
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} else {
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let provides = currentInstance.provides
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// by default an instance inherits its parent's provides object
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// but when it needs to provide values of its own, it creates its
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// own provides object using parent provides object as prototype.
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// this way in `inject` we can simply look up injections from direct
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// parent and let the prototype chain do the work.
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const parentProvides =
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currentInstance.parent && currentInstance.parent.provides
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if (parentProvides === provides) {
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provides = currentInstance.provides = Object.create(parentProvides)
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}
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provides[key as any] = value
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}
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}
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export function inject<T>(key: InjectionKey<T> | string): Ref<T> | undefined
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export function inject<T>(
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key: InjectionKey<T> | string,
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defaultValue: T
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): Ref<T>
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export function inject(key: InjectionKey<any> | string, defaultValue?: any) {
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if (!currentInstance) {
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// TODO warn
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} else {
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// TODO should also check for app-level provides
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const provides = currentInstance.parent && currentInstance.provides
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const val =
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provides && key in provides ? (provides[key as any] as any) : defaultValue
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return isRef(val) ? val : ref(val)
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}
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}
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